When I first purchased my FF TD6 I had a strange vibration ( hard to describe but like a humming vibration) when driving up a steep hill and applying the foot to a accelerator at about 80kph. Almost like it was bogging down. I replaced the injector loom with a new genuine loom and the problem went away.

Recently a couple of times I have had this "humming like feeling" vibration occur on a slight incline, or when moving off from stand still any suggestions,
(Injector harness & Injectors have replaced not so long ago. so rule them out)